The busa wasn't my first bike but I hadn't been riding for very long when I jumped on mine. I'm kind of moving away from the big girl, because I prefer riding on the track and I use the busa as my street bike. I'm sure she could be a good time there too but I don't track anything I'm not willing to wad up and throw away.
Prove them wrong? Maybe I did. People were thinking(betting) i was going to have some type of accident when i got this bike but I've done alright. No tickets, no accidents...a few OH SHAT moments. Getting on a fast bike was ok for me, but not for the majority of people I come across. I spent my first summer riding getting used the bike. The next summer i noticed I was starting to get a little too comfortable and maybe even a little bit of a squidish... so I bought a liter bike and started going to the track. Turns out the track was exactly what I was looking for and now that is where I do most of my riding.
Do it again? The rocket ship acceleration of these bikes is something that has to be experienced to be understood. Heck, not even everyone that owns one has the guts to really open them up. However, with the added benefit of 20/20 hindsight, when I found what I really enjoyed in about motorcycle riding I think an SV650 with a tuned up suspension would have suited me just fine.
Biggest thing is to know yourself. When starting out, if you don't think you have the self restraint to handle something like this, don't get it.